The present invention discloses an apparatus for forming and screening a large-scale single-layer two-dimensional liquid droplet array, and a use method thereof. The apparatus comprises a micro-column array chip, a scraping plate for auxiliary spreading of a liquid droplet, a probe for controlling the liquid droplet, a three-dimensional translation table and other components, wherein a micro groove unit for trapping the single liquid droplet is formed by using the gap between micro-columns, and the liquid droplet is spread in the micro groove unit in a single-layer and single manner through gravity effect and capillary effect or through an auxiliary means so as to form the single-layer liquid droplet array. With the apparatus of the present invention, the accurate positioning and detection on the liquid droplet, the sucking on the target liquid droplet and the subsequent treatments can be performed. According to the present invention, the apparatus has characteristics of simple structure and easy operation; and the method has advantages of fast liquid droplet spreading, high flux, high liquid droplet trapping efficiency, liquid droplet position fixing and the like, and is suitable for single cell analysis and screening, single molecule analysis and screening, high-throughput gene screening, protein directed evolution, antibody screening, microbial research, drug screening, and other fields.